Dow Jones Industrial Average

A price-weighted stock market index that tracks 30 large, publicly owned blue-chip companies trading on U.S. exchanges.

The Dow Jones Industrial Average (DJIA) is a price-weighted stock market index that tracks 30 large, publicly owned blue-chip companies trading on the New York Stock Exchange and the Nasdaq. Established in 1896, it is one of the oldest and most widely followed equity benchmarks in the world. Unlike market-capitalization-weighted indices, the Dow is price-weighted, meaning that companies with higher nominal stock prices exert a greater influence on the index's movements, regardless of their total market value. To calculate the index, the stock prices of all 30 constituent companies are added together and then divided by the Dow Divisor. The divisor is a continuously adjusted figure that accounts for corporate actions like stock splits, spin-offs, and structural changes to the index's membership. This adjustment ensures that such events do not artificially distort the value of the index. Investors and market commentators monitor the Dow as a quick gauge of the overall health of the U.S. economy and mature corporate giants. However, because it contains only 30 stocks, critics argue it is less representative of the broader market than more comprehensive indices like the S&P 500. A common pitfall is overestimating a market rally or decline based solely on the Dow, as a sharp move in just one or two high-priced components can disproportionately skew the entire index's performance.

Suppose the Dow consists of only three stocks: Company A at $100, Company B at $50, and Company C at $30, with a Dow Divisor of 0.18. The index value is calculated as ($100 + $50 + $30) / 0.18 = 1,000. If Company A's stock price rises by 10% ($10) to $110, the new index value is ($110 + $50 + $30) / 0.18 = 1,055.56. If Company C's stock price instead rises by 10% ($3) to $33, the new index value is ($100 + $50 + $33) / 0.18 = 1,016.67, demonstrating how higher-priced stocks have a larger impact on the index.